Hydraulic piston motor



June 9, 1942. R. K. JEFFREY ET AL. 2,285,863

HYDRAULIC PISTON MOTOR M Original Filed May 6, 1938 //Yl/ENTOE s I EQBERT K. JEFFREY,

AND

y LEWIS EMITCHELLIDECE'PSED, Emu/v20 D. NICHOLS, ADMINISTRATOR,

BY film", I

l TTY.

Patented June 9, 1942 HYDRAULIC PISTON MOTOR Robert K. Jeffrey, Columbus, Ohio, and Lewis E. Mitchell, deceased, late of Columbus, Ohio, by Richard D. Nichols, administrator, Columbus, Ohio, assignors to The Jeflrey Manufacturing Company, a corporation of Ohio Original application May 6, 1938, Serial No. 206,448, now Patent No. 2,263," 9, dated November 25, 1941.

Divided and this application November 4, 1940, Serial No. 364,327

6 Claims. (01. 309-4) This invention relates to a hydraulic piston motor and particularly to the construction of a piston for such a motor.

An object of the invention is to provide an improved piston construction for a hydraulic piston motor which is substantially leak-proof under very high pressures.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

This application is a division of our application Serial No. 206,448 filed May 6, 1938, for an improvement in Mining machines, now Patent No. 2,263,779 dated November 25, 1941.

In the accompanying drawing:

Fig. 1 is a diagrammatic plan view showing a mining machine incorporating the structure of our invention;

Fig. 2 is a longitudinal sectional elevational ing machine showing the hydraulic piston motor comprising a feature of the invention herein claimed;

Fig. 3 is an enlarged sectional view of half of the piston'herein claimed shown attached to the piston rod; and

Fig. 4 is a front view of a fragment of the piston shown in Fig.9 and the piston rod to which it is connected. I

In Fig. 1 of the drawing there is illustrated diagrammatically a mining machine which incorporates the features of the invention herein claimed. The mining machine is disclosed in full detail in our parent application above identified, of which this application is a. division, and so no -attempt will be made to describe it in detail in its entirety, only those parts forming the subject matter of the invention herein claimed being specifically described.

Said mining machine includes a truck 45 which supports a turntable 1| upon which is mounted for'adjustment in a vertical plane a supplerespect to the supplementary frame I00. As seen in Fig. 2 of the drawing, the previously mentioned elongated neck I09 ,is provided at opposite ends with spaced apart journal bearings, one of which is seen at I39, upon which is Journaled a cylinder I40.

As clearly illustrated in Fig. 2 of the drawing. the forward and lower end of the cylinder I is provided with an integral drum I46 within which drum is rotatably mounted a cylindrical shell I48. The shell I48 is provided with a pair of end plates, one of which is seen at I50, which plates are rigidly butremovably attached to said shell I46, as by machine screws. It is thus to be seen that the shell I48 provides an enlarged bearing contact withthe interior vof the drum I46 and is mounted for rotation with respect to said drum I46 about the longitudinal axis of said shell I48 and drum I46.

Adjacent their bottoms the end plates are provided with semi-cylindrical flanges I52 which cooperate with a flanged split ring I53 rigidly attached to a supporting plate or casting I54 as by screws I55, which plate I54 carries a cutter the head mechanism I59 about a generally transverse axis.

Cutter. chain I5! is driven from an electric motor forming part of supplementary frame I 00 andthrough gearing terminating in shaft I19 I and sprocket I81 as fully disclosed in our parent mentary frame I00 which has a forwardly ex- .a considerable amount of mechanism which per se is not pertinent to the invention herein claimed.

Attention. is directed particularly to Fig. 2

I and to the structure of the turnover head mechanism I59 and to certain of the operating means therefor which are adjustabiy supported with application above identified.

To provide'for the pivotal movement of the kerf cutting mechanism I60 on the transverse 230 (Fig. 2) comprising a cylinder 23l is bolted to the top of cylinder I40 carried on neck I09. The piston motor 230 is of the double acting type and thus the cylinder 24 is provided with inlet ports 252 and 233 adjacent its head'and piston rod end, respectively.

Within the cylinder 23I is a piston indicated generally by the reference character 234, the structure of which is illustrated in full detail in Figs. 3 and 4 of the drawing and is described hereinafter. The piston 234 is mounted upon a of which is seen at 244, which are pivotally attached by pins to integral bifurcated brackets 3 .carried adjacent the tops of, the end plate of the turnover head mechanism 153. It will thus be evident that by controlling the supply of hydraulic pressure to the piston motor 238 the cross-piece 238 may he slid forwardly and rearwardly with a. consequent pivotal movement of the kerf cutting mechanism 168' about the axis of the end plates of turnover head mechanism 153.

Attention is now directed particularly to Figs. 2, 3 and 4 and to the detailed construction of the composite piston 234 which has been found very effective to provide a high eflicient seal so that the kerf cutting mechanism 158 may be piston rod 235 which extends through a stufling locked in any desired position where it will be held substantially indefinitely due to the fact that there is no leakage of fluid past piston 234. Said piston 234 is formed by a central plate 241 which is threaded onto the threaded portion 248 of piston rod 235 and is provided withwrench receiving notches 243 to provide for its adjustment. on opposite sides of the plate 241 are plates 258 and 251 which are also threaded upon the threaded portion 248 and are provided with wrench receiving notches 252 and 253, respectively. I

Toprevent any leakage of hydraulic fluid by the threads between plate 258 and piston rod 235, we provide a copper wire gasket 254 between them which will be compressed when plate 258 is screwed as far as possible against a shoulder provided by virtue of the reduced size of threaded portion 248 with respect to piston rod 235.

Between the plates 241-and 258 we provide a ring-shaped washer or packing cup 255 of composition material having an enlarged peripheral flange 256 which turns in a left-hand direction, as viewed in-Fig. 3 of the drawing. The flange 256 is spaced slightly from the plate 258 so that pressure oil extending through the passageway 281 will find its ,way between said'plate 258 and the flange 256 to force said flange 256 outwardly in intimate sliding contact with the interior surface of the cylinder'231. The portion of the cup 255 which is parallel with the plates 241 and 258 I Y is rigidly clamped between them and may be held in place by integral circular projections 251 on I said plates 258 and 241. Between the plates 241 and 251 there is provided another ring-shaped washer or'packing cup 258 similar in construc- Y plate 258 is screwed down tightly against it. Cup

255 is then placed on plate 258 and plate 241 is then screwed tightly in place. Cup 258 is then tion to cup 255 except that its peripheral flange put in place and plate 251 is screwed tightly against it.

To insure the maintenance of the parts in their positions the end of the threaded portion 248 is provided with a diametrical groove 259 and a hole 288 is drilled parallel therewith extending into each of the notches 253 of plate 258. Extending through one of the holes 268 we place a cotter key 281, the head of which extends into the groove 258 and the ends of which are bent over, as clearly illustrated in Fig. 303 the drawing. This cotter key 281 will, of course, prevent relative movement between the plate 251 and the piston rod 235.

It is evident from the above description that we have provided a simple but very eflective piston construction which has been found in practice to be very eflicient in operation, particularly in that it is substantially free of leakage even under very high pressures, and consequently the cutter bar 188 will be retained in any position to which it is adjusted and hydraulic fluid on opposite sides of the piston 234 is locked in the cylinder 231 as described in complete detail in our parent application above identified.

It is to be noted that the bore 281 and the plate 258 insures that any compressed fluid on that side of the piston 234 will be transmitted to the inner face of the flange 258 of cup 255.

Furthermore, it is to be noted that said inner face of the cup.255 is spaced slightly from the adjacent surface of the plate 258 and thus any hydraulic pressure to the left of piston 234 is transmitted to push the flange 255 outwardly in contact with the inner surface of the cylinder 251. The relation between the cup 258 and the plate 251 is quite similar to that between cup 255 and plate 258. These cups 255 and 258 are of course reversely positioned and the cup 255 is principally eifective to prevent any flow of hydraulic fluid to the right with respect to piston 234 and cup 258 is principally eflective to prevent any reverse flow of hydraulic fluid.

There are no passageways or bores in plate 251 similar to bores 281 in plate 258, but the spacing of the periphery of cup 258 or plate 251 at least in a large measure insures the presence of pressure on the inner surface of the peripheral portion of cup 258 to eflect the hydraulic seal desired.

It is also to be noted that the leading edge of flange 258 of cup 255 terminates in a relatively sharp point adjacent its outermostperipheral edge which also aids in the insurance of a fluidtight seal formed thereby. The cup 258 is of course similarly formed.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and we therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of our. invention, what we desire to secure by Letters Patent of the United States is:

1. A hydraulic piston motor comprising a cylinder, a piston rod in said cylinder having a threaded portion, a piston or said rod, said piston comprising a central plate, end plates one on each side of said central plate and threaded on said thread portion, wiping washers compressed between said end plates and said central plate, a sealing ring between one of said end plates and said piston rod, and means for locking the other end plate to said rod comprising a cotter key comprising a central plate, end plates one on each side of said central plate and threaded on said thread portion, cup-shaped wiping washers compressed between said end plates and said central plate, one of said end plates having a transverse passageway near its periphery in communication with the inside peripheral portion of the adjacent washer, and means for;locking the other end plate to said rod.

3. In combination a piston rod and a piston, said piston including a plate threaded on the end of said piston rod, a bore in said plate, a groove in one end of said piston rod, and locking means extending through said bore into said groove.

4. Apparatus oi the class described comprising the combination with a piston rod having a transverse groove in one end, of a piston screw-threaded onto such end of the piston rod. and locking means extending through a hole in said piston into said transverse groove to prevent said piston from being unscrewed from said piston rod.

- 5. Apparatus oi the class described comprising the combination with a piston rod having a recess in one end, of a piston screw-threaded onto such piston rod end, and a cotter pin extending from said recess through a hole in said piston to lock the piston against being unscrewed from said piston rod.

6. Apparatus oi the class described comprising the combination with a piston rod having a diametrical slot in one end, of a piston screwthreaded onto such end of the piston rod, and means extending radially from one end or said slot into a recess in said piston to lock the latter relative to said piston rod.

ROBERT K. JEFFREY. RICHARD. D. NICHOLS, Administrator of the Estate of Lewis E. Mitchell,

Deceased. 

